package top.tagao.features_01_lambda;

import org.junit.jupiter.api.Test;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Consumer;
import java.util.function.Predicate;

/**
 * java内置的4大核心函数式接口
 *
 * 消费型接口 Consumer<T>     void accept(T t)
 * 供给型接口 Supplier<T>     T get()
 * 函数型接口 Function<T,R>   R apply(T t)
 * 断定型接口 Predicate<T>    boolean test(T t)

 * @author fu-xiao-liu
 * @Date 2022/3/20 11:50
 */
public class Lambda_02 {

    public void happyTime(double money, Consumer<Double> con) {
        con.accept(money);
    }

    @Test
    public void test1() {
        happyTime(500, (money) -> System.out.println("花费：" + money));
    }

    @Test
    public void test2() {
        List<String> list = Arrays.asList("北京", "南京", "天津", "东京", "西京", "普京");

        filterString(list, (s) -> s.contains("京")).forEach(System.out::print);

    }


    //根据给定的规则，过滤集合中的字符串。此规则由Predicate的方法决定
    public List<String> filterString(List<String> list, Predicate<String> pre) {

        ArrayList<String> filterList = new ArrayList<>();

        for (String s : list) {
            if (pre.test(s)) {
                filterList.add(s);
            }
        }

        return filterList;

    }
}